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ralphb writes "Here is the story of scientists in China who have, for the first time, used cloning techniques to create hybrid embryos that contain a mix of DNA from both humans and rabbits. Hop on over for a look!"

Of course! Sorry, clarification: It's the really huge rabbits we have to worry about, and the really fast rabbits. Small rabbits that are not fast at attacking armored men and killing them, merely present the same troubles as tribbles.

It comes down to where you think human life begins - in my opinion (and no doubt, not yours), human life begins at the point where the fetus can survive on its own. Until then, it's a parasite, and the host should be able to deal with it as the host sees fit.

Wait, you say, does that mean that someone who is dependant upon machines to live is somehow less human than someone who can survive autonomously?

Again, this is the fallacy of false equivalence. One human is in a state of deterioration. The other is in a state of growth and development.

Once the eeg is flat in an adult human being, it will not recur. Using a flatt eeg to define death, or the end of life, was arrived at biologically. A flat eeg indicates the death of the human being. Individual components may continue on for a few hours or days, but the organism as a whole is dead.

It's a common misconception to call someone who is pro-choice a "pro-abortionist". Most "pro-choice" people that I know don't go around encouraging pregnant women to have abortions. None of the pro-choice women I know have ever had an abortion.

In regards to your comment about a fertilized egg being a human being, well... I think that depends on what you mean. Is it genetically distinct from its parents? Yes. Does it contain human DNA? Yes. Is it a person? Debatable. A fertilized egg does not have a brain, a personality, or any sense of its environment. Is it possible to lack these qualities and still be considered human? That's a matter of viewpoint.

Sit outside any Wal-Mart and observe the fact that cattle-like humans already exist...

As for rabbits... couldn't they have picked a cooler species to intermix with? Wolves, cheetahs (fast sprinters for the Olympics!), bears... hmph.
Definitely not primates though... anyone seeing 28 Days Later should put the kibosh on that one.

No... you didn't read the article. I just can't believe it. In order for this to happen, the embryo would have to be transferred to a womb. All the samples were destroyed. They don't believe a hybrid could even survive. That's not what this research is for.

These probably would not survive gestation. There are factors spread out in a specific manner in an egg which tell the various parts of the embryo what to become, and when. Imagine the egg as a bag of concentration gradients, going along at least three axes, several gradients per axis. As the cell divides, these become compartmentalized into individual cells. You now have scores of little bags with codes to each one, the code being the concentration of several factors (factors ABCDE having respective concentrations of 4,3,1,2,6 or 5,4,0,8,9). At certain times, these factors come together and give signals that tell that cell or group of cells to become a certain progenitor tissue type. Differentiation goes further after that, with cells "deciding" what to become based on what kind of cell is nearby.

Many of the signals would be similar between human and rabbit, but probably not enough to make a viable human, or viable anything else for that matter. The rabbit DNA control sequences targeted by the factors that are in the egg would probably be too different from the sequences with similar function in human DNA. This would permit the embryos to survive through several divisions, and probably form simple embryos (mammals are very similar until the fetus stage....even then, it's hard to tell sometimes). But it would probably never make it through gestation. Probably.

The team said it retrieved foreskin tissue from two 5-year-old boys and two men, and facial tissue from a 60-year-old woman, as a source of skin cells. They fused those cells with New Zealand rabbit eggs from which the vast majority of rabbit DNA had been removed.

If you thought rotten.com was bad, just wait until foreskinrabbitface.com goes live.

To clone human stem cells in China:1) Look for woman to let you jam a needle into her ovary2) Get kicked in the nads3) Buy rabbits4) Jam a needle in rabbit ovary5) Stick random human cell nucleus in egg you sucked out6) ???7) Stem Cells!!8) Claim to have created rabbit-babies9) Wait for science-illiterate newsmen to promote your stock symbol on TV10) Profit!!

What a bunch of fuckholes. Seriously, when the best scientific information in your article's coming from the Vatican, I think you're in trouble.

It's not a mutant. They inserted human chromosomes into a rabbit *egg* cell. Only the mitochondrial DNA (the one that is provided by the egg, comes from the mother, and has little to do with heredity as a whole) came from the rabbit.

Why is this important ? Well, because the ability to make valid human stem-cells from animal egg cells would remove one of the most troubling objections to human stem cell research : right now, the only valid egg cells for human cloning are human eggs - aka ovules. These must be obtained from real women, which leads to technical and ethical problems (I know that in the US selling ovules is already common practice but in Europe things are quite different). At any rate, a woman can only produce one egg per month, so this is a poorly productive method.

(The other solution for obtaining stem cells is to suppress the cloning phase and to directly take existing human stem cells out of embryos - there again, moral problems arise if commercial forces are ever allowed in this game).

Making human stem cells with animal eggs suppress most of these problems. The only big problem that remains is simply that so far, it didn't work. Now these people claim that they have made "mostly human" stem cells with rabbit eggs, but will they have the same capacitie as purely human stem cells ? Could the mitochondrial (rabbit) DNA interfere with the functioning of the cell ? These are the important questions now. According to this article, the paper seems to address none of them.

I will remind them that I could be useful in rounding up people to toil in their underground carrot mines

bunnies aren't just cute as everybody supposesThey got them hoppy legs and twitchy little nosesAnd what's with all the carrots?What do they need such good eyesight for anyway?Bunnies, bunnies, it must be bunnies

Lyrics by Josh Whedon [letssingit.com], reproduced without permission because, hey, its the internet and everyone does it...

This is just the sort of thing that will catch the attention of do-gooder congressmen and get things like cloning research completely banned...If they do things like this, they should keep it quiet, not get it out into the mainstream of public opinion where people can jump (or maybe hop-hop-hop) to conclusions and phone their congressman.

The vast majority of the DNA in the embryos is human, with a small percentage of genetic material -- called mitochondrial DNA -- contributed by the rabbit egg.

Ok guys. I'm all in favor of stem cell research, but . . . we need to just stop and figure out a way to do it without generating shocking headlines. This kind of headline is just going to piss everyone off and hinder the progress of the research.

It would be wrong to keep it quiet - and people would find out anyway. Just keep it below a certain

Actually, I suggets that this is just the sort of thing that must be presented correctly, rather than kept quiet about. It is a useful and viable scientifc endeavour, not just a "Hey, let's put a cat in a blender and see what happens!" type of experiment.

It should be phrased in as scientifically opaque a way as possible though, so that the tabloid journalists can't understand it;-)

Are you kidding? Our politicians are only green with envy that this did not take place in America, so that they could claim credit for it.

The whole point of this excercise was to find a way to get stem cells for research. Apparently they think this method is quite likely to work.

Do you remember a little thing about stem cells? Wasn't there a little spat or two about it? This is a huge breakthrough which can allow both sides to be happy. Although the human-embryo stem cell proponents do lose some face, because there really was another way to get the stem cells.

The thing is, the religious right will still have a field day with this and try to ban it, too. It's not so much "another way of getting stem cells" as it is the same way -- only using a donor egg from another species.

You're still using human DNA -- probably the whole human nucleus in a cell that is allowed to become a fetus. The major difference between all animal embryos is the DNA of the nucleus, so essentially you have a human embryo w/ mitochondria that are unique from other humans. Mitochondrial D

Probably, but perhaps this will have the opposite effect. When it is clear that a country like China, who already has a significant impact on the economy of the US, is able to make advances in the embryonic stem cell area that we aren't due to regulations, that could end up being a strong argument to relax restrictions in the US. Probably not in the short term, but when and if stem cell related treatments become mainstream and if it turns out that embryonic stem cells are the only/best/cheapest/something way to go then we'll have to see whether voters will elect officials who will make it possible for that research and treatment to be done here in the US.

Even regular cloning causes most of the subjects to die. I can't imagine interspecies cloning not killing many many more. Most likely, this embryo will die after a few divisions, being so strange. However, even "successful" clones have more problems and a shorter lifespan. Doing this should be unethical by anyone's standards.

You guys are completely missing the point.... it's neither disgusting, nor disturbing. It is a viable and exciting research path that could someday lead to cures for many chronic diseases. To quote the article:

"Most important, researchers said, the paper stops short of proving beyond a doubt that the stem cells retrieved from the hybrid embryos are truly capable of growing for long periods of time in lab dishes, and that they can turn into every known kind of cell."

Of course, if you read the article, you'd realize that they're not going to develop the "clone" to have any lifespan--they're trying to create a method to harvest stem cells (without the need for abortions).

I thought China needed to control the exponential growth of their population, do they really need that? They should sell the technology to the state of Florida instead...

I don't get it... why does Florida need population growth? It's full of all the nearly dead retirees who migrate downwards from every other state. Please tell me you're not suggesting we need more breeding from that population?

The vast majority of the DNA in the embryos is human, with a small percentage of genetic material -- called mitochondrial DNA -- contributed by the rabbit egg. No one knows if such an embryo could develop into a viable fetus, though some experiments with other species suggest it would not.

The DNA that they put into the human cells is not DNA which determines physical charateristics. It's mitochondrial DNA, which is found in the cells' mitochondria. These little organelles of the cell basically burn sugar to make energy usable for the rest of the cell. There is a lot of evidence suggesting that the mitochondria found in all human cells was actually a seperate organism that became co-dependent with the cells in which they lived. Interstingly enough, mitochondiral is almost totally unaltered with a new generation, and is always passed down through the female of the species because the sperm cells typically have very few or a negligible amount of mitochondria. i.e. You have the same mitochondrial DNA as your mother and all your siblings, and she has all the same as her mother and so on down your family tree.

Hate to nitpick, but this is a really important point from an ethical standpoint. The eggs that were collected were from rabbits. The rabbit nuclear DNA was removed, and replaced with human DNA.

It's the same end result--an egg with human nuclear DNA and rabbit mitochondrial DNA--but the original eggs were harvested from rabbits. This is potentially a very useful technique, because it represents a source of embryonic stem cells that doesn't require the coll

Judgeing from the artical they might have found a better way to get stem cells for research. However, now instead of having to deal with just people that are anti-cloning or anti-stem cell research, you would also have to deal with the animal rights activists because of the retrevial of the eggs, and the undertermined status of the cells after they are created.
So in the short run it is posibly a better way to get stem cells, in the long run it will raise alot of ethical concerns, as well as the undermined nature of the cell - in short we don't know if they are "true" stem cells in their ablity to grow into any organ. Also, if they do have the potenital to become any organ, we don't know how the human body would react to the foegin DNA (the rabit mitocadria)

Better use sharks, or hawks, or even snakes. But not rabbits. What's good in mixing human intellect with rabbit sexuality? Now imagine big spiders with human brains. That would be a certain improvement for both.

RTFA and you'll find the cells used for the DNA were a mix of rabbit skin and human foreskin. Imagine explaining that when your long-eared, buck-toothed teenager asks "Daddy, where do babies come from?"

I don't claim to be a DNA expert but I'll bet the people opposing these kinds of exparaments know even less about DNA than I do.

Somewhere I've read that we share most of our DNA with all the other members of the animal kingdom and indeed we share a lot of DNA with every living thing.

Some of these exparaments are "pure research" and others are "applied research." In pure research you do the exparament and then look to see where it took you. In applied research you have a pretty good idea of where you are going and are pretty much conducting the exparament to verify your theory. In either case, there really is a goal to the research and I'll submit that the goal is usually good for humanity.

Without this kind of research we would miss out on opportunities to cure disease, treat birth defects and, all sorts of other good things. But, there is something even better that comes from this research. We gain a greater understanding of the world we live in. We add to humankinds knowlege base. Without doing this we will fail to advance and the next century will look like the last. When that happens there is little doubt that we will have started to slide down the road to extinction becuase we will exhaust vital resources.

One thing to keep in mind about embryonic development is that it progresses in stages, and different genes kick in at different stages. Just because cells divide in a petri dish, or progress to some stage of development, is not an indication that it will develop into a viable organism.

For example, if a human embryo with three of a given chromosome is formed, depending on which chromosome it forms on, the embryo may either fail to develop past the 8 cell stage, or develop into a 10 week fetus and die, or develop longer and die, but never become viable outside the womb. Down's syndrome is unique in that it and sex chromosome triploidies are the only triploidies that are compatible with life. Other triploidies result in miscarriage or failure to implant.

Small nitpick. You're referring to trisomy, not triploidy. Trisomy (in humans) refers to an inadvertant tripling of one chromosome; triploidy is the result of an extra (third) copy of all chromosomes. Triploidy is usually the result of two sperm fertilizing a single egg. (Oops.) Trisomy (or monosomy, where the fetus is one chromosome short) is usually the result of an uneven division of genetic material when sperm or egg was formed.

Triploid fetuses usually spontaneously abort, though some will survive to term--in which case their life expectancy is less than a month.

As you noted, some trisomies are survivable; most are not. More details here [niu.edu].

Interesting aside: Some species (particularly plants) tolerate polyploidy quite well, having tetraploid or hexaploid genomes (four or six sets of chromosomes). Odd numbers of sets are infertile, but again are often tolerated in plants--this infertility is sometimes a desired trait, as in seedless watermelons and grapes.

if the US wasn't strictly trying to control embryonic stem cells for research, then there wouldn't be a demand to make a hybrid source for embryonic stem cells.

america (currently) leads because we (usually) have the foresight to keep barriers out of the way of technological progress. we have slowly overcome nearly every 'religious' boundary by slowly letting people become accustomed to the way this medical technology -improves- life. each time they are accused of wanting to 'play god'. scientists grit and bear the well-intentioned but factually ignorant viewpoint until slowly the advances are accepted.

i'm not saying that we throw our morals to the wind and race to immortality and superhuman hybrids - just that we redirect our skepticism. are we really trying to play god? or are we just trying to preserve and extend life, to ease pain and suffering, and to advance as much of our species as we can, without hurting anyone? instead of just levelling opposition to every potential breakthrough because we're 'playing god' - can't we just look for a second at what the facts are?

embryonic stem cells are being harvested from aborted fetuses. fetuses that were legally terminated and currently, are waste. by banning science from using this unfortunate situation to the best of their ability, people are ensuring that absolutely no good comes from the situation.

if lives can be saved by studying those who have left - then why in the world would we stand in the way of that? religious opposition in the 19th and early 20th century maintained that if we allowed study of cadavers or donation of organs that people would be killed and abducted and harvested by notorious individuals in the name of 'science'. but that did not happen. nor will people go out of their way to abort fetuses just so they can get stem cells. scientists are not growing fetuses to harvest stem cells.

this unfortunately ignites the whole abortion debate, which i doubt will ever be resolved. but legally, if I, as next of kin, have the right to determine whether the body of a loved one is to be donated to science; why shouldn't these mothers who exercised their legal right to terminate their pregnancies, also have that same legal right to donate?

I've never understood where this idea comes from. When you have sex, the number of sperm released is typically in nine figures {decimal}. Out of all those sperm, most will not fuse with an egg. Perhaps one {single birth or identical twins} or rarely two {non-identical twins}, even rarer more than two. Most likely, none of them will find an egg.

If a man has sex just once and gets his girlfriend pregnant, one sperm has done its job but there are still hundreds of millions of sperm wasted. Now if a man had sex twice a day every day for seventy years and each instance of sex conceives exactly one child, that is just over 50000 babies - and trillions of sperm. Most of which were just never going to make it. So if you had a w**k twice a day for seventy years you might have wasted trillions of sperm, but since most of them were never really going to go anywhere anyway, you have only really wasted one per shot. And there are sufficiently more sperm in a single ejaculation to make that quite insignificant by comparison.

As they say, sperm are tiny, but it only takes one of them to fill a pram!

First off, they had to remove virtually all the rabbit nuclear DNA because if you do not do this and simply fuse two cells (say a human cell and a rabbit cell) with intact DNA, almost invariably, the human DNA is lost. The cells dump extraneous DNA and it just happens that most often, it is the human chromosomes that get dumped.

Second, this is merely a gradation of "chimera" beyond that which is commonly called a "transgenic". The later is a long-used basic tool in molecular biology/developmental research. There are innumerable extant mouse-human "chimeras" out there, just as there are Drosophila-human, yeast-human, yeast-E. coli, E. coli-yeast, etc, etc, etc, transgenic (chimeras). Normally, what is transfered in these cases are individual genes, though short chromosomal segments can be transfered as well. This article refers to a chimera in which it is merely the shell that contains the DNA (the cell) that is changed from native to alien species. You could likely get by with a viable cell with a partial mix of rabbit genes in human cells and vice versa, so long as the proteins encoded by the genes are homologous enough to share the same functions and helper proteins.

What would be cool, in my opinion, would be to do a human-bird hybrid in which the bird cell contains only human genomic DNA but the cells retain avian mitochondria - with a little transgenic work done to replace the human mitochondrial genes in the nuclear chromosomes with their avian counterpart. Why? IF (a relatively big if) the mitochondria can properly function in concert with the rest of the human DNA, you might produce a long-lived cell line or, if you let it go to term, a longer lived human. Why? This is based on the oxidative damage/free radical theory of aging: bird mitochondria are much more efficient than human mitochondria on the level of producing energy (ATP) vs production of damaging oxygen radicals. Birds have a high metabolism and their lifespan, relative to metabolic rate (one of the supporting observations for the free radical theory of aging), is unusually long. In general, a higher metabolic rate equates to a correspondingly shorter lifespan. The predominant source of damaging radicals is mitochondria by far. So, if you replace the human mitochondria with super-efficient, low radical producing bird mitochondria, you could end up with a human with an extended lifespan (to unknown extent) if the free radical theory of aging is largely correct.

Such a person would be no less human than anyone else, their mitochondria would simply be that of a bird rather than a human. Big deal. Mitochondria are alien themselves, afterall. They are the remnant of the fusion, hundreds of millions of years ago, between an anaerobic-type cell and a cyanobacteria-like aerobic bacteria. Once upon a time, then, a chimera was formed based on a semi-parasitic melding of two separate species. Each gains benefit from the other and ultimately, you end up with aerobic eukaryotic cells that makes humans, dogs, birds, insects, reptiles, etc.

Ok, I was almost down to the bottom of the page moderating, and had to back out to respond to this point.

You have come close to hitting on the quintessential question behind all of the debate.

What makes a human a human?

Arguably, the most important criteria for being human is awareness... consciousness.

Here's a rather graphic gedanken:

Shave off all your hair... are you still human?
What if you amputate your arms and legs?
How about body organs? Artificial heart, kidney dialysis, iron lung, etc...
Take this beyond what is possible with modern day science... brain in a vat. Quality of life has certainly decreased dramatically! However, the brain is still thinking, the software of mind is still running. What if it were possible to run the software on other hardware? Sure, cyberpunk has beat this topic to death... but I certainly don't consider my brain to be me! To quote Rene Descartes: "cogito ergo sum". Nothing else is relevant... software is everything (yeah, I'm a programmer;-) )

Unfortunately, science has not been able to answer the question of when during development the spark of consciousness begins.

Can we agree that awareness requires a brain? Can we agree that this brain needs to be working... ie. the synapses are firing, neural potentials exist?

If so, then consciousness must begin sometime between 4 and 6 months of development.

This experiment was limited to 14 days of development. This is the point when cells begin to differentiate. Clearly this is long before a brain and the potential for consciousness arises.

Really, this is an ideal stop-gap measure. If by mixing mitochondrial DNA of another species with human nuclear DNA you achieve a development term necessary for medicinal purposes, and at the same time insure development self-aborts prior to brain development, then you end up with a self regulating procedure that prevents the accidental creation of a human consciousness.

You should not bring Chinese morality into this, since US researchers have tried this too. from the WP article:Although scientists in Massachusetts had previously mixed human cells and cow eggs in a similar attempt to make hybrid embryos as a source of stem cells, those experiments were not successful.

Secondly, this was done to produce stem cells and not out of morbid curiosity. Please, I know this is/., but RTFA!

The 'perceived benefit' you can't see is eventually to create a source of stem cells without using aborted foetuses.

This kind of knee-jerk 'this is bad/immoral/whatever' comment, even though you clearly didn't finish (start?) reading the article is exactly the kind of piss-poor commentary that prevents science doing good.

Whether or not this particular research was ethical or not, there should still be boundaries set up. We cannot justify the experiments Nazi's did in the name of science, merely because it's "knee-jerk" to stop it.

You don't need rabbit-human hybrids. However, medical researchers do need stem cells to pursue a huge number of research goals, including growing new organs, repairing damaged tissue, regrowing nerves etc. That research is being hampered by concerns from a lot of groups about harvesting stemcells from aborted embryos. Hence this research to create an alternative source of stem cells.

In other words, this IS important research, that has the potential of providing important material for research projects that might take medical science huge leaps forwards.

Not really - mitochondria, as I understand it, work at a pretty basic level, generating ATP from fairly basic biological material (fatty acids, glucose, etc.). They're sort of the 'last step' in the long and complex chain of conversions called 'metabolism'.

Also as I understand it, mitochondria across all procaryotes (anything with cell nuclei, i.e. 'not bacteria') are all derived from the same ancestral bacterium that first formed a cooperative partnership with another cell, and are still fairly similar.